" A DOZEN PHALLACIES WOMEN BUY
Phallacy 1.
If he loves me, he'll be faithful forever.
Truth
His loving you has nothing to do with his being faithful. Some men are monogamous. Most aren't. The sexy ones usually aren't. Monogamy lasts three, days, three weeks, three months, or at best three years with most men. Often it lasts just about long enough to get you pregnant. Nature has a reason for this. Men are programmed to spread their seed as widely as possible and women to raise live, healthy babies. Human babies take a long time to grow up to self-sufficiency.... Some few paragons of maleness are faithful. Most others cheat. The question is: can you stand it? If the cheating is not blatant and disrespectful and you get a lot out of the relationship in other ways (a friend, a lover, a father to your kids, an economic partner), then consider these alternatives: you can accept his cheating gracefully, and at the same time extract emotional and financial benefits from his guilt. You can cheat discreetly yourself -- if (and only if) you enjoy it (not for spite). You can realize it has nothing to do with you. He does it for his manhood, not against your womanhood "

― Erica Jong , Fear of Fifty: A Midlife Memoir